probe

Synopsis

Interface Level

Solaris DDI specific (Solaris DDI). This entry point is required for non-self-identifying devices.
You must write it for such devices. For self-identifying devices, nulldev(9F) should
be specified in the dev_ops(9S) structure if a probe routine is not necessary.

ARGUMENTS

dip

Pointer to the device's dev_info structure.

Description

probe() determines whether the device corresponding to dip actually exists and is a
valid device for this driver. probe() is called after identify(9E) and before attach(9E) for
a given dip. For example, the probe() routine can map the device registers
using ddi_map_regs(9F) then attempt to access the hardware using ddi_peek(9F) or ddi_poke(9F) and
determine if the device exists. Then the device registers should be unmapped
using ddi_unmap_regs(9F).

To probe a device that was left powered off after the last
detach(), it might be necessary to power it up. If so, the
driver must power up the device by accessing device registers directly. pm_raise_power(9F) will be
not be available until attach(9E). The framework ensures that the ancestors of the
node being probed and all relevant platform-specific power management hardware is at full
power at the time that probe() is called.

probe() should only probe the device. It should not change any software state
and should not create any software state. Device initialization should be done in
attach(9E).

For a self-identifying device, this entry point is not necessary. However, if a
device exists in both self-identifying and non-self-identifying forms, a probe() routine can
be provided to simplify the driver. ddi_dev_is_sid(9F) can then be used to determine whether
probe() needs to do any work. See ddi_dev_is_sid(9F) for an example.